Telephoto objective



SEARCH ROOM May 1953 BERTELE 2,833,181

TELEPHOTO OBJECTIVE Filed Oct. 1a, 1956 I k Fig.1

' United States Patent 2,833,181 Patented May 6, 1958 Example 2 z 833 181 [Relative aperture 1:4. Focal length 100 mm. p 36.1 mm.]

36.84 TELEPHOTO OBJECTIVE 5 Li 41 05 i= 6.84 7M=L52000 v=63.fi Ludwig Bertele, Heerbrugg, Saint Gallen, Switzerland L, 86'71 i2= 2. 42 reezes 11:41.9

T3= Application October 18, 1956, Serial No. 616,743 n=+ 63 Claims priority, application Switzerland L3 69100 November 2, 1955 27 24 =25. 79

L t= 1.53 =l.548l4 =45.9 3 Claims. (CI. 88-57) "a 85 4 What I claim and desire to secure by Letters Patent The present invention relates to a telephone objective 1 of the United States is: consisting of three air-spaced components and showing 1. A telephoto objective fully corrected for the diifera relative aperture of about 1:4 and an angle of view ent errors of image. said objective comprising four lenses of about 25 to 30. The objective is constructed of divided into three air-spaced components, the front comfour single lenses arranged in such a manner that the ponent being positive and being composed of a biconvex positive element towards the ob ect being composed of and a biconcave lens, the middle component being a a biconvex and a biconcave lens, the second element single biconvex lens and the third component being a formingasingle biconvex lens and the third element being single diverging lens and bent towards the image, in a single diverging lens bent towards the image. It proved whichthat in spite of this small number of single lenses it is possible to construct an efi'icient objective which favours1 and are i an spaces between the components abl can be a H d in c a ti i d1 buiwm i to t the thickness of the lenses,

y pp e amerais i g y f; 2 the focal length of the first component (L and L segment shutter behind the ob ective due to a path of f the focal length of the second com onent (L rays claiming but a small free diameter of the segmenti p 3 Shutter I p the distance between the rear surface (r,) of the bjective and the image The conditions to be observed according to this inven- 0 tion are the following. F the total focal length of the ob ective,

and which are within the limits specified in the following Egg F algebraic relationship:

a (a) 2F f 6 F (c) 0.45 F p 0.27 F (b) F f 631F 1+ i+ 1+ 3+ i+ i+p' F (c) 0.45 F p' 0.27 F where F t +t +s +t +s +t +p' 0.95 F

2. A fully corrected 100 mm. focal length telephoto 1 and 1h h in p f th l the Components, 40 objective having substantially the following charactert; to t e t ic esses o e enses, i i f the focal length of the first component (L and L f the focal length of the second component (L ri=+ 34.80 p the distance between the rear surfaces (r of the 4263 Fl-52542 objective and the image 4? Li zi= 1. s9 n.j=l.G6T55 v=4l.9 F the total focal length of the objective. 81:26 11 62.95 An objective embodying the present invention is given L3 n= 2. 03 i=1. 09100 v=54.8 in Examples 1 and 2 and illustrated in the respective 82:31. 89 Figures 1 and 2. L to L; are the respective lens L 25. 79 r 4 9 elements. The radii of curvature (r), the thicknesses 50 7208 5481. of lenses (t) and the axial air distances (s) are consecutively numbered from the object. The diaphragm is w i denoted by symbol 5, the shutter by 6 and the image by 7. the respective lens elements The glasses of the lenses forming the ob ective are charr147 the radii of curvature acterized by the refraction index for the d-line n in 50 114 the thicknesses of the lenses 032153211; with their colour dispersion by the Abbe s1 and S: the air spaces between the lenses n the refractive index for the d-line The lenses L and L; can be unceniented single lenses. Abbe numben Example 1 fully corrected IQO mm. focal length telephoto ob ective having substantially the following character- [Relatlve aperture 1:4. Focal length 100mm. p 36.1 mm} istics:

34,30 n=+ 36. 84 L t1= 5. 79 7ld=1.52542 v=64.5 Ll ii= 6. s4 M=L52000 v=63.6

n=- 42.63 T2= 41.05 L: iz= 1. S9 ns=1.66755 v=41.9 L2 ii= 2.42 n=j=1. 66755 17:41.9

fs=+ 64.55 26 11 n=+ 86.71 s 26 u 8i= i= 72.63 L, i== 2.63 1ld=1.69100 v=54.8 LII n iq= 6.32 n =1 6910O v=54.s

n=-1s2.s2 r5=l20. 56

25 79 s:=31.89 27 24 $25.19 L n zi= 1.58 'ns=1.54814 i=4 L4 t4= 1.58 7ld=1.54814 v=45.9

3 wherein are:

L -L the respective lens elements r r the radii of curvature t -t the thicknesses of the lenses s and s; the air spaces between the lenses n the refractive index for the d-line v the Abbe number.

References Cited in the file of this patent UNITED STATES PATENTS Aldis May 19, 1896 Tronnier Dec. 15, 1953 Bertele Sept. 11, 1956 FOREIGN PATENTS Great Britain Sept. 19, 1938 

